1. Field of the Invention
This invention relates to additives for improving lubricating characteristics of lubricating oils and more particularly, to lubrication boosting additives which, when added to lubricating oils for use in power engines, can improve load bearing properties of the oils and can prevent wear of the power engines while mitigating the lowering of an energy efficiency owing to the friction. The invention also relates to a lubricating oil composition comprising the lubricating boosting additive mentioned above.
2. Description of the Prior Art
As is known in the art, lubrication boosting additives have been used in order to improve lubricating characteristics of lubricating oils. Typical examples of the commercially sold additives include suspensions of polytetrafluoroethylene (PTFE) and molybdenum disulfide in the form of fine powder.
PTFE is a resin which has good lubricating characteristics and a high chemical resistance, but is inconveniently insoluble in almost all the types of solvents, thus making it impossible to use PTFE as a solution. This is why PTFE is used in the form of a fine powder in a suspension in practical applications. However, the use of the suspension involves a serious problem with respect to its compatibility with or dispersability in lubricating oils. For instance, the fine powder may settle in the suspension prior to use or after mixing with lubricating oils. Alternatively, the fine powder may deposit on power engines or may clog filters therewith.
Moreover, the fine powder of PTFE or molybdenum disulfide does rarely contributes to the improvement of the load bearing properties when added to lubricating oils.